Polyoxyalkylene/unsaturated diester reaction product for cellular foam stabilization

ABSTRACT

Polyoxyalkylene surfactants for cellular foams can be prepared by reacting a polyoxyalkylene adduct and an esterified unsaturated dibasic acid in the presence of a free-radical initiator.

This is a division of application Ser. No. 544,301, filed Oct. 21, 1983,now U.S. Pat. No. 4,481,307 which is a division of application Ser. No.426,581, filed Sept. 29, 1982, now U.S. Pat. No. 4,418,158, which is adivision of application Ser. No. 282,322, filed July 10, 1981, now U.S.Pat. No. 4,365,024.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the preparation of novel surfactants and theirutilization in producing cellular foam materials, particularly phenolic,isocyanurate and urethane foams. The surfactants can be prepared byreacting under free radical polymerization conditions a polyoxyalkyleneadduct and an esterified unsaturated dibasic acid.

2. Description of the Prior Art

It is known in the manufacture of cellular polymeric materials toutilize small quantities of various cell stabilizing additives, such assilicones, in order to improve the foam's cell quality. While thesilicone surface active agents contribute to the production of foamedproducts having a combination of desirable properties, siliconesurfactants are relatively expensive materials.

Another highly effective cellular foam stabilizer of the prior art isthe capped reaction product of an alkoxylated amine and acopolymerizable mixture of dialkyl maleate and N-vinyl-2-pyrrolidinoneor N-vinyl caprolactam, which is disclosed in U.S. Pat. No. 4,140,842.However, this foam stabilizer is also relatively expensive and has beenfound to consist of a complex mixture whose components must be separatedfrom each other to realize their particularly desirable cellular foamstabilizing properties.

It would accordingly be highly desirable to provide a novel surfaceactive agent which would be relatively simple and inexpensive to produceand still have good foam stabilizing characteristics.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a novelclass of surfactants for use in preparing fine, closed-cell foammaterials, particularly phenolic, isocyanurate and urethane foams, and amethod of producing the surfactants, as well as a method of producingthe foams by use of the surfactants.

It is another object of the present invention to provide closed cellpolymeric foam materials of high quality and laminated building panelsemploying the foam materials.

It is still another object of the present invention to produce closedcell polymeric foam materials with high thermal resistance and highinsulation properties and a relatively slow increase in thermalconductivity with time.

It is a further object of the present invention to produce polymericfoam materials which exhibit a high closed cell content withoutadversely affecting friability, compressive strength and the lowflammability characteristics of the materials.

It is a still further object of the present invention to provide closedcell polymeric foam materials which can be used in building panels whichare highly insulating, thermally resistant, low in friability,soundproof and self-supporting.

These and other objects and advantages of the present invention willbecome more apparent by reference to the following detailed descriptionand drawings wherein:

FIG. 1 is a side schematic representation of an apparatus suitable forproducing a cellular foam material in accordance with the presentinvention;

FIG. 2 is a cross-sectional view of a laminated building panel havingone facing sheet; and

FIG. 3 is a cross-sectional view of a laminated building panel havingtwo facing sheets.

DESCRIPTION OF THE INVENTION

The above objects have been achieved by the development of an improvedsurfactant for foam materials, particularly phenolic, isocyanurate andurethane foams, which is the reaction product of an unsaturated diesterand a polyoxyalkylene adduct.

More particularly, the foam surfactant of the present inventioncomprises the reaction product of an esterified unsaturated dibasic acidcontaining 4 or 5 carbon atoms and a polyoxyalkylene adduct in thepresence of a free radical initiator. The unsaturated diester can beprepared by reacting together an unsaturated dicarboxylic acid or acidderivative with an alcohol whose hydrocarbon radical can be saturated orunsaturated. The unsaturated diester can also be prepared from a mixtureof alcohols.

In the broadest aspects of the present invention, the esterifiedunsaturated dibasic acid can be reacted with any conventionalpolyoxyalkylene adduct. The polyoxyalkylene adduct can be represented bythe structural formula

    H--polyoxyalkylene chain).sub.t R,                         (I)

wherein R is an organic or inorganic radical and t is the number ofpolyoxyalkylene chains reacted onto the R backbone. Preferably, R is anorganic radical selected from aromatic, aliphatic, cycloaliphatic, andheterocyclic radicals, and combinations of these, and t is an integerfrom 1 to 50, more preferably 1 to 8, most preferably 1 to 4. Includedamong the conventional polyoxyalkylene adducts which can be employed asstarting materials are anionic, cationic and nonionic type surfactants.These surfactants may be used either alone or in admixture with eachother. Non-ionic type surfactants are preferred.

Among the conventional polyoxyalkylene adducts which can be employed arethe alkylene oxide adducts of:

(a) Mono- and polyhydroxyalkanes and mono- and polyhydroxycycloalkanes;

(b) Alkanolamines;

(c) Mono- and polyamines;

(d) Non-reducing sugars and sugar derivatives;

(e) Aromatic amine/phenol/aldehyde condensation products;

(f) Phosphorus and polyphosphorus acids;

(g) Mono- and polyhydric phenols;

(h) Amides;

(i) Organic carboxylic acids;

(j) Hydroxyl containing triglycerides;

(k) Polysiloxanes; and the like.

The adducts are prepared in known manner. Preferably, the alkyleneoxides employed in the adduct formation have 2 to 4 carbon atoms, forexample, ethylene oxide, 1,2-epoxypropane, the epoxybutanes, andmixtures thereof. Mixed propylene oxide-ethylene oxide adducts haveproved especially useful. In the preparation of the latter adducts, theethylene oxide and propylene oxide are advantageously reacted in themolar ratio of 10:90 to 90:10.

It has been found that the molecular weight and alkylene oxide contentof the conventional polyoxyalkylene adducts can play an important rolein determining the cell stabilizing capacity of the surfactants of theinvention. More specifically, certain adducts have been found to requirea minimum ethylene oxide or propylene oxide content and molecular weightfor more efficient cell stabilization. These requirements can vary fordifferent polyoxyalkylene adducts and foam systems but it is possible toestablish the satisfactory values for any given foam through routineexperimentation.

Advantageously, the mono- and polyhydroxyalkanes and mono- andpolyhydroxycycloalkanes to be alkoxylated for use in the presentinvention can have from 1 to 8 hydroxyl groups. Illustrative alcoholsfor alkoxylation include, among others, ethylene glycol, propyleneglycol, 1,3-dihydroxypropane, 1,3-dihydroxybutane, 1,4-dihydroxybutane,1,4-, 1,5-, and 1,6-dihydroxyhexane, 1,2-, 1,3-, 1,4-, 1,6- and1,8-dihydroxyoctane, 1,10-dihydroxydecane, glycerol,1,2,4-trihydroxybutane, 1,2,6-trihydroxyhexane, 1,1,1-trimethylolethane,1,1,1-trimethylolpropane, pentaerythritol, xylitol, arabitol, sorbitol,mannitol, 3,4-dihydroxycyclopentane, tetramethylolcyclohexanol,cyclohexanediol, fatty alcohols, high molecular weight polyoxyalkyleneglycols; and the like.

Another useful class of polyoxyalkylene adducts which can be employedare the alkylene oxide adducts of alkanolamines. Illustrativealkanolamines include ethanolamine, diethanolamine, triethanolamine,triisopropanolamine, and tributanolamine.

Another useful class of polyoxyalkylene adducts which can be employedare the alkylene oxide adducts of mono- and polyamines Mono- andpolyamines suitable for reaction with alkylene oxides include, amongothers, methylamine, ethylamine, isopropylamine, butylamine,benzylamine, aniline, the toluidines, naphthylamines, ethylenediamine,diethylene triamine, triethylenetetramine, 4,4'-methylenedianiline,1,3-butanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,2-, 1,3-,1,4-, 1,5- and 1,6-hexanediamine, phenylenediamines, toluenediamine,naphthalenediamines, and the like.

A further class of polyoxyalkylene adducts which can be employed are thealkylene oxide adducts of the nonreducing sugars and the nonreducingsugar derivatives. Among the nonreducing sugars and sugar derivativescontemplated are sucrose, alkyl glycosides such as methyl glucoside,ethyl glucoside, and the like, glycol glycosides such as ethylene glycolglucoside, propylene glycol glucoside, glycerol glucoside, and the like.

A still further useful class of polyoxyalkylene adducts are the alkyleneoxide adducts of mono- and polyhydric phenols, including mononucleardihydroxy benzenes, higher alkyl phenols, and polyphenols. Among thephenols which can be used are found, for example, catechol, resorcinol,orcinol, nonylphenol, bisphenol A, bisphenol F, condensation products ofphenol and formaldehyde, more particularly the novolac resins,condensation products of various phenolic compounds and acrolein, thesimplest members of this class being the1,2,3-tris(hydroxyphenyl)propanes, condensation products of variousphenolic compounds and glyoxal, glutaraldehyde, and other dialdehydes,the simplest members of this class being the1,1,2,2-tetrakis(hydroxyphenyl)ethanes, and the like.

Another desirable class of polyoxyalkylene adducts are the alkyleneoxide adducts of aromatic amine/phenol/aldehyde condensation products.The condensation products are prepared by condensing an aromatic amine,for instance, aniline, toluidine, or the like, a phenol such as phenol,cresol, or the like, and an aldehyde, preferably formaldehyde, atelevated temperatures in the range of, for example, from 60° C. to 180°C. The condensation product is then recovered and reacted with alkyleneoxide, using a basic catalyst (e.g., potassium hydroxide) if desired, toproduce the adducts.

The alkylene oxide adducts of phosphorus and polyphosphorus acids areanother useful class of polyoxyalkylene adducts. Phosphoric acid,phosphorous acid, the polyphosphoric acids such as tripolyphosphoricacid, the polymetaphosphoric acids, and the like are desirable for usein this connection.

Included among the polyoxyalkylene adducts of the present invention arethe alkylene oxide adducts disclosed in U.S. Pat. No. 3,383,351, theteachings of which are hereby incorporated by reference.

Examples of commercially available polyoxyalkylene adducts for use inthe present invention include Polyglycol 15-200 from Dow ChemicalCompany, Flo Mo 36 C and 5D from Sellers Chemical Corporation,ethoxylated sorbitan esters from Imperial Chemical Industries andPluronics from BASF Wyandotte Corporation.

In an advantageous embodiment of the invention, the ester of theunsaturated dibasic acid used in preparing the cell stabilizers of thisinvention corresponds to the formula:

    T.sup.1 O.sub.2 C--C.sub.u H.sub.2u-2 --CO.sub.2 T.sup.2

wherein u is 2 or 3 and T¹ and T² are identical or different andrepresent a straight or branched, saturated or unsaturated hydrocarbonchain which preferably contains 4 to 18, more preferably 8 to 18, carbonatoms. Typical examples of the esters that may be used include dibutylmaleate, dibutyl fumarate, dibutyl itaconate, dioctyl methylenemalonate,diisooctyl maleate, dioctyl maleate, ditridecyl maleate, and dioleylmaleate, preferably dioleyl maleate, dioctyl maleate and ditridecylmaleate, most preferably ditridecyl maleate.

Evidence indicates that the mechanism by which the unsaturated diesterreacts with the polyoxyalkylene adduct is by grafting, i.e., thereaction product is composed of the polyoxyalkylene adduct backbone towhich are attached at intervals "grafts" of the unsaturated diester. Inlight of the known inability of unsaturated diesters of the invention tohomopolymerize, it is believed that the mechanism of the reaction mayinvolve the addition of single diester units to the polyoxyalkylenebackbone. Even in cases where the amount of grafting is somewhat lessthan 100%, the reaction product nevertheless exhibits a cell stabilizingcapacity. Unreacted unsaturated diester can be removed from the totalreaction product by conventional methods, such as by solvent extraction.Since a substantial amount of unreacted diester can reduce stabilizerefficiency, excess diester should generally be removed from the reactionproduct. The reaction product of the invention includes both the totalreaction product and the reaction product minus unreacted diester.

The surfactant compositions of the invention are produced by reactingtogether the unsaturated diester and polyoxyalkylene adduct in thepresence of an effective amount of any conventional free-radicalinitiator known to be suitable for the graft polymerization ofethylenically unsaturated monomers. Illustrative initiators are thewell-known free radical type of vinyl polymerization initiators, forexample, the peroxides, persulfates, perborates, percarbonates, azocompounds, etc., including hydrogen peroxide,1,1-bis(t-butylperoxy)cyclohexane, dibenzoyl peroxide, acetyl peroxide,benzoyl hydroperoxide, t-butyl perbenzoate, t-butyl hydroperoxide,di-t-butyl peroxide, lauroyl peroxide, butyryl peroxide,diisopropylbenzene hydroperoxide, cumene hydroperoxide, paramenthanehydroperoxide, diacetyl peroxide, di-alpha-cumyl peroxide, dipropylperoxide, diisopropyl peroxide, isopropyl-t-butyl peroxide,butyl-t-butyl peroxide, dilauroyl peroxide, difuroyl peroxide,ditriphenylmethyl peroxide, bis(p-methoxybenzoyl)peroxide,p-monomethoxybenzoyl peroxide, rubrene peroxide, ascaridol, t-butylperoxybenzoate, diethyl peroxyterephthalate, propyl hydroperoxide,isopropyl hydroperoxide, n-butyl hydroperoxide, t-butyl hydroperoxide,cyclohexyl hydroperoxide, trans-decalin hydroperoxide,alpha-methylbenzyl hydroperoxide, alpha-methyl-alpha-ethyl benzylhydroperoxide, tetralin hydroperoxide, triphenylmethyl hydroperoxide,diphenylmethyl hydroperoxide, alpha,alpha'-azo-2-methyl butyronitrile,alpha,alpha'-2-methyl heptonitrile, 1,1'-azo-1-cyclohexane carbonitrile,dimethyl alpha,alpha'-azo-isobutyrate, 4,4'-azo-4-cyanopentanoic acid,azobisisobutyronitrile, persuccinic acid, diisopropyl peroxydicarbonate, and the like; a mixture of initiators may also be used.

The efficiency of the initiator is conditioned upon its beingsufficiently active under the polymerization conditions employed.Particular conditions affecting the initiators's efficiency are, forexample, the reaction temperature (in the range from about 30° to about150° C.), and the nature of the adduct(s) being modified, and, where ametal catalyst(s) is employed, its nature.

Although the efficiency of the initiator is acceptable when it is usedalone, an organo transition metal catalyst can be added with theinitiator to accelerate the reaction. The preferred metal catalyst isferrocene. Suitable organometallic catalysts are disclosed in U.S.patent application Ser. No. 113,841, the teachings of which are herebyincorporated by reference.

The free-radical initiated reaction of this invention can be conductedunder conditions known to be suitable for free-radical polymerizations,using, e.g., solution, bulk, emulsion, or suspension techniques. It hasbeen found especially useful to carry out the reaction on theunsaturated diester and polyoxyalkylene reactants alone in the presenceof the initiator and optionally the metal catalyst.

The reaction is advantageously carried out by mixing the reactants,initiator(s) and optionally metal catalyst(s) at temperatures from about30° to about 150° C. under an inert atmosphere such as that provided bynitrogen and like inert gases until reaction is complete. The reactionis continued until consumption of the unsaturated diester ceases, asdetected by conventional analytical methods, such as gel permeationchromatography. Reaction times of 1 or more hours can be expected.

The initiator(s) and optional metal catalyst(s) can be added at thebeginning of the reaction or can be added portionwise at intervalsduring the course of reaction. Similarly, the polyoxyalkylene adduct andesterified unsaturated dibasic acid can be brought together at thebeginning of the reaction or can be combined in increments as reactionproceeds, such as by the gradual addition of the diester to a resinkettle containing the adduct.

In a preferred embodiment of the invention the unsaturated diesterconstitutes between about 5 and 40, more preferably 10 and 30 weightpercent of the reaction mixture. The unsaturated diester comprises about20 weight percent of the reaction mixture in a most advantageous andpreferred embodiment of the invention. The concentration of initiator(s)in the mixture is advantageously within the range of about 2 to 30weight percent, preferably 4 to 25 weight percent, based on the totalweight of diester(s) present. Generally, the optional metal catalyst(s)is utilized at a level of 0.001 to 0.1 grams per gram of initiator.Preferably, 0.001 to 0.06 grams of metal catalyst(s) per gram ofinitiator are used.

The molecular weight of the conventional polyoxyalkylene adduct to becopolymerized can vary over a wide range. However, if the molecularweight is too low, the foam prepared with the subsequently preparedcopolymerization product gives coarse cells. No comparable limitationhas been found in the case of conventional polyoxyalkylene adducts ofhigher molecular weights. The latter adducts can be utilized in thehighest molecular weights currently available to yield fine-celled foamsin accordance with the present invention. As previously indicated, thesuitable molecular weight and alkylene oxide content for any particularadduct and foam system is readily determinable by those skilled in theart. In general, the starting material alkoxylated adduct will have amolecular weight of above about 1000, and advantageously in the range ofapproximately 2000 to 12,000. The molecular weight can be determinedfrom the equation:

    M.W.=(56.1×1000×f)/OH

where

M.W.=molecular weight of the polyoxyalkylene adduct,

f=functionality, that is, average number of hydroxyl groups per moleculeof polyoxyalkylene adduct, and

OH=hydroxyl number of the polyoxyalkylene adduct.

In certain foam systems it is desirable that the conventionalpolyoxyalkylene adduct used in the present invention be treated with asuitable agent to cap its hydroxyl groups. Suitable capping agents arethose organic compounds capable of reacting with compounds containingactive hydrogen groups, such as hydroxyl groups, as determined by theZerewitinoff method. The capping agents convert the hydroxyl groups ofthe polyoxyalkylene adduct to groups which are substantially chemicallyinert in the cellular foam-forming mixtures of the invention. Thecapping reaction takes place under conditions well known in the art; as,for example, described in Sandler, S. R. and Karow, "Organic FunctionalGroup Preparations," Organic Chemistry, A Series of Monographs Edited byA. J. Blomquist, Academic Press, New York and London, 1968 Edition,pages 246-247, 1971 Edition, Vol. II, page 223 and 1972 Edition, Vol.III, page 13, the descriptions of which are incorporated herein byreference. The capping treatment may take place either before or afterthe copolymerization. Suitable capping agents include organic acids,acid anhydrides, acid chlorides, and acyloxy chlorides, such as a loweralkyl monocarboxylic acid having 1 to 10 carbon atoms selected from thegroup consisting of acetic acid, propionic acid, butyric acid, hexanoicacid, octanoic acid, decanoic acid, isomers of these acids, anhydridesof these acids, acid chloride derivatives of these acids and mixturesthereof. Acetic anhydride is readily obtainable and convenient to use.Similarly, aromatic acids, anhydrides and chlorides can be employed.Benzoyl chloride and substituted products of it such as3,5-dinitrobenzoyl chloride are examples of these. Alkyl and aromaticisocyanates can also be employed. Other factors, such as solubility inthe polyoxyalkylene adduct being treated and the solubility of thecapped surfactant in whatever resin system is to be stabilized, areconsiderations of which a practitioner in the art is cognizant inselecting the capping system which will yield the desired closed cellstabilized foam. Examples of suitable capping agents are acetic acid,acetic anhydride, acetyl chloride and 3,5-dinitrobenzoyl chloride. Thepreferred capping agent is acetic anhydride. The capping treatment istypically performed at temperatures ranging from 50° to 140° C. and isadvantageously carried out until the surfactant has a hydroxyl value ofless than 50, and preferably less than 10. The hydroxyl number isdetermined by the ASTM-D 1638 test. It may be highly advantageous incertain foam systems to strip off any acid formed during the cappingtreatment, as, e.g., the acetic acid formed in using acetic anhydride ascapping agent. The capped reaction product of the claims includes boththe stripped and unstripped product.

One of the preferred surfactants of the present invention is the cappedor uncapped product of the reaction of an unsaturated diester and anethoxylated castor oil. The latter material is prepared by ethoxylatingthe hydroxy groups on the triester of ricinoleic acid. For purposes ofthe present invention, it is advantageous that the resulting ethoxylatedproduct contains at least 25 moles of ethylene oxide per mole of castoroil. The ethylene oxide content is preferably 25 to 60, most preferably35 to 40, moles per mole of oil.

Another preferred surfactant of the invention is the capped or uncappedproduct of the reaction of an alkoxylated amine having the formula:##STR1## wherein R¹ is independently an alkoxylated chain having theformula: ##STR2## s is an integer from 2 to 10 inclusive and the ratiop:q is from 10:90 to 90:10, and an unsaturated diester. The unsaturateddiester is preferably a dialkyl maleate wherein the alkyl of the maleatehas 8 to 18 carbon atoms. Examples of preferred dialkyl maleates aredioctyl maleate, ditridecyl maleate and dioleyl maleate.

The alkoxylation is carried out in a known manner using a mixture ofethylene oxide and propylene oxide in the molar ratio of 10:90 to 90:10and preferably from 40:60 to 60:40. The molecular weight of thealkoxylated amine is from 1500 to 12,000 and preferably from 2500 to6000. If the molecular weight of the alkoxylated amine is less than1500, foam collapse can occur.

In the reaction of the unsaturated diester with the above alkoxylatedamine of formula III, the unsaturated diester advantageously comprisesbetween 5 and 40 weight percent of the reaction mixture, and preferably20 weight percent of the reaction mixture. The alkoxylatedamine/unsaturated diester reaction product is advantageously capped byreacting it with acetic anhydride.

Instead of employing branched polyols, such as the alkoxylated amine offormula III above, as the polyoxyalkylene adduct of the invention,linear polyols may advantageously be used. Examples of such adducts arethe linear polyols based on propanediols, supplied under the name"Pluronics" by BASF Wyandotte Corporation. Pluronic polyols are blockcopolymers of ethylene oxide and propylene oxide. One type of Pluronicsconsists of a central block of propylene oxide units with ethylene oxideblocks on each end. For any particular polyol series of this type,propylene oxide is added to 1,2-propanediol to attain a desired chainlength and then various levels of ethylene oxide are added to achievethe desired ethylene oxide:propylene oxide ratio. Another type ofPluronic are the Pluronic R series of polyols wherein ethylene oxide isfirst polymerized onto 1,3-propanediol, followed by the polymerizationof propylene oxide onto the resulting ethoxylated structure. Thealkoxylation of the Pluronics is carried out in a known manner.

The products obtained by reacting together a polyoxyalkylene adduct andunsaturated diester in accordance with the present invention can beutilized as cellular foam stabilizing surfactants. By cellular foamstabilizing surfactants are meant those which keep the foam fromcollapsing and rupturing. Surfactants obtained in accordance with thisinvention are found to be especially useful cell stabilizers inphenolic, isocyanurate and urethane foam. They have the capability ofgiving fine-celled, low k-factor foams.

The surfactant of the invention is employed in a cell stabilizing amountin the foam-forming composition of the invention. Generally, thesurfactant comprises from 0.05 to 10, and preferably comprises from 0.1to 6, weight percent of the composition. Too little surfactant fails tostabilize the foam and too much surfactant is wasteful. Thosesurfactants which are non-ionic are particularly good cell stabilizers.In certain foam systems, e.g., involving polyisocyanurate and phenolicpolymers, the capped polyol is preferred.

The surfactant of the present invention is particularly useful in theproduction of a closed-cell cellular composition comprising a phenolicresin and blowing agent in addition to the surfactant. Phenolic resinfoams are a well-known class, phenol-aldehyde resin foams beingrepresentative and proportions of blowing agent and catalyst componentsbeing well known in the art.

Foams of low friability can be obtained by using a preferred phenolicpolymer described in Moss U.S. Pat. No. 3,876,620, the disclosure ofwhich is incorporated herein by reference. The preferred phenolicpolymer is an alkylol group containing phenolic polymer of the formula:##STR3## wherein R² is ##STR4## hydrogen or a radical of the formula:##STR5##

The R³ 's are independently selected from the group consisting of loweralkyl, preferably of 1 to 4 carbon atoms, phenyl, benzyl, halo,preferably chloro, bromo, or fluoro, nitro, and hydrogen. The R⁴ 's areindependently selected from the group consisting of ##STR6## hydrogen,or a radical of above Formula VI.

The R⁵ 's are independently selected from the group consisting of loweralkyl, preferably of 1 to 4 carbon atoms, hydrogen, phenyl, benzyl, orfuryl. By furyl is meant the radical introduced by the use of furfural.In above Formula V, x is an integer from 2 to 10 inclusive and ispreferably an integer from 2 to 6 inclusive. When x is less than 2, afoam produced from such a phenolic polymer tends to have too high afriability. On the other hand, as x exceeds 10, the viscosity of thepolymer increases to the point where it is difficult to process thefoam. The phenolic polymers of the present invention generally have amolecular weight between 300 and 2,000. At lower molecular weights, theresultant foams tend to have too high a friability, whereas at highmolecular weights the viscosity of the phenolic polymer, even when asolvent is present, tends to be too high to permit processing.

A preferred subclass of phenolic polymers are those of the formula:##STR7## wherein R² is HOCH₂ --, hydrogen or a radical of the formula:##STR8##

The R⁴ 's in above Formulas VII and VIII are independently selected fromthe group consisting of HOCH₂ --, hydrogen or a radical of above FormulaVIII.

In a preferred embodiment of the present invention, at least one of theR⁴ 's is methylol, i.e., HOCH₂ --. This is to ensure that there will becross-linking sites on the phenolic polymer. Of course, it is well knownin the art that such methylol groups or, when the aldehyde is other thanformaldehyde, alkylol groups, are automatically introduced into thepolymer by the process described below.

In the broadest aspects of the present invention, the phenolic polymercan contain widely varying ratios of the radicals of Formula VI or VIIIto ortho-cresol units. However, this ratio is generally from 1:3 to 10:1and is preferably from 1:1 to 4:1. At higher ratios, i.e., a deficiencyof ortho-cresol, the cellular material produced from such a phenolicpolymer tends to be too friable. In determining the above ratios, onemust include the radicals of Formula VI or VIII present in Formula V orVII, respectively. The phenolic polymers of the invention can besynthesized by the methods described in U.S. Pat. No. 3,876,620.

The phenolic compositions useful in the present invention generallycomprise the phenolic polymer of Formula V or Formula VII, together witha compound of the formula: ##STR9## wherein the R³ 's are independentlyselected from the group consisting of lower alkyl, preferably of 1 to 4carbon atoms, phenyl, benzyl, halo, preferably chloro, bromo, or fluoro,nitro, and hydrogen.

The compound of Formula IX can be present in the phenolic composition inwidely varying ratios of Compound IX to the polymeric composition but isgenerally present in a weight ratio of 1:30 to 1:2 and is preferablypresent in a weight ratio of 1:20 to 1:5. Examples of suitable compoundsof Formula IX include among others: m-cresol, m-chlorophenol,m-nitrophenol, 3,5-xylenol, and phenol, i.e., hydroxy benzene. Phenol isthe most preferred compound of Formula IX because of cost, availability,and reactivity. The phenolic polymers of Formula V and Formula VII areproduced according to the present invention by combining the reactantsin a two-step process described in Moss, U.S. Pat. No. 3,876,620.

In the broadest aspects of the present invention, any aldehyde can beemployed to produce useful phenolic polymers. Examples of suitablealdehydes include, among others, furfural, formaldehyde, benzaldehyde,and acetaldehyde. Formaldehyde is the preferred aldehyde. Formaldehydecan be employed in widely varying forms such as the 37% aqueous solutionwidely known as formalin. However, it is generally necessary to removefrom the polymeric material the water introduced with the formalin.Formaldehyde is preferably employed in the form of paraformaldehydewhich contains much less water.

The cellular material of the present invention is formed by simplyreacting the alkylol group containing phenolic polymer of Formula V orFormula VII and the compound of Formula IX under conditions such that acellular product will result. As is well known in the phenolic foam art,the reaction can be conducted in the presence of a foaming catalyst, ablowing agent, and a surfactant. The reaction can be performed betweentemperatures of 10°-50° C., preferably 15°-25° C., and conveniently atatmospheric pressure. The cellular materials of the present inventiongenerally have a thermal conductivity k-factor value of from 0.1 to 0.3,and preferably from 0.1 to 0.2 Btu/hr-°F.-sq. ft. per inch as measuredat 24° C. The k-factor value is measured on a Model 88 machine suppliedby the ANACON Company. The friability of the cellular material is 20% orless. Friability is the propensity of the foam to break expressed inpercent weight loss. This is determined by the ASTM C-421 friabilitytest conducted for 10 minutes.

In the broadest aspects of the present invention, any catalyst whichwill enhance the cross-linking and foaming reaction of the phenolic foamforming mixture can be employed in the present invention. However, thepreferred foaming catalysts are aromatic sulfonic acids, examples ofwhich include, among others, benzene sulfonic acid, toluene sulfonicacid, xylene sulfonic acid, and phenol sulfonic acid. Phosphoric acidcan also be employed either alone or in admixture with the sulfonicacids. The preferred sulfonic acid is a mixture of equal parts by weightof toluene sulfonic acid and xylene sulfonic acid, as described inMausner et al. U.S. Pat. No. 3,458,449. Another foaming catalyst whichhas been found to give excellent results is a blend of toluene sulfonicacid, phosphoric acid, and water in a weight ratio of 35-50:50-35:15.

The catalyst is generally present in the minimum amount that will givethe desired cream times of 10 to 120 seconds and firm times of 40 to 600seconds to the reacting mixture. The catalyst, however, generallycomprises from 0.5 to 20, and preferably comprises from 1.0 to 15,weight percent, based on the weight of the cellular material.

Any blowing agent characteristically employed in similar prior artproducts, such as is described in Moss et al., U.S. Pat. No. 3,968,300,can be employed in the phenolic foam forming composition of the presentinvention. In general, these blowing agents are liquids having anatmospheric pressure boiling point between minus 50° and 100° C. andpreferably between zero and 50° C. The preferred liquids arehydrocarbons or halohydrocarbons. Examples of suitable blowing agentsinclude, among others, chlorinated and fluorinated hydrocarbons such astrichlorofluoromethane, CCl₂ FCClF₂, CCl₂ FCF₃, diethylether, isopropylether, n-pentane, cyclopentane, and 2-methylbutane. Combinations oftrichlorofluoromethane plus 1,1,2-trichloro-1,2,2-trifluoroethane, arethe preferred blowing agents. The blowing agents are employed in anamount sufficient to give the resultant foam the desired bulk densitywhich is generally between 0.5 and 10, and preferably between 1 and 5pounds per cubic foot. The blowing agent generally comprises from 1 to30, and preferably comprises from 5 to 20 weight percent of thecomposition. When the blowing agent has a boiling point at or belowambient, it is maintained under pressure until mixed with the othercomponents. Alternatively, it can be maintained at subambienttemperatures until mixed with the other components.

The cellular phenolic product formed by using the surfactant of theinvention has a uniform, fine-celled structure. Uniformity of cells isdetermined by visual and microscopic examination. This property ofproducing a fine-celled foam is tested by mixing 2 to 5% of thesurfactant with the phenolic composition and producing a foam asdescribed herein.

The average cell size diameter should ideally be less than 0.2 mm and ismore preferably less than 0.1 mm (ASTM D-2842). Fine-celled foams can bythe means set forth in the invention be rendered closed cells. Theblowing agent is then trapped in the cells. One means of expressing thecontainment in the cells of the blowing agent is by use of the k-factordrift value. Unfaced cellular materials containing fluorocarbon gas haveinitial k-factors in the vicinity of 0.1-0.2 at 24° C. This low valueincreases over a period of months or sometimes days. The change isexpressed as the k-factor drift. The k-factor is measured at a meantemperature of 24° C. The value is redetermined at various timeintervals up to about 1000 days. A material exhibiting fast k-drift willattain a k-factor (BTU/hr-°F.-ft² per inch thickness) of at least 0.2within 25 days. A slow k-drift material may require between 200 days andover two years to attain a 0.2 value. Any material which possesses ak-value under 0.2 will provide high thermal resistance. Obviously, thelonger this value or a lower value is maintained, the better theefficiency.

Ball, Hurd, and Walker have published a comprehensive discussion ofk-factor changes as a function of time. ("The Thermal Conductivity ofRigid Urethane Foams", J. Cellular Plastics, March/April, 1970, pp66-78). F. Norton ("Thermal Conductivity and Life of Polymer Foams", J.Cellular Plastics, January, 1967, pp 23-37) has shown that diffusion offluorocarbon gases out of unfaced foam and infusion of air into the foamcauses an increase in k-factor. A slow k-drift foam is defined as onethat attains a k-factor at 24° C. of 0.15-0.17 after 200-400 days andthen remains below 0.2 k-factor for 5-10 years. Eventually allfluorocarbon diffuses from the foam to leave a closed cell materialwhich contains only air in the cells.

The k-factor for the closed cell foam containing only air falls in therange of 0.22-0.26 BTU/hr-°F.-ft² per inch thickness at 24° C. for the2-3 lbs/ft³ density range. Therefore, if a foam exhibits greater than0.2 k-factor after a short period of time (less than 25 days), thensubstantially all fluorocarbon has diffused from the foam and has beenreplaced by air. On the other hand, if the k-factor remains below 0.2for at least 100 days, then a substantial amount of fluorocarbon gasremains in the closed cells of the foam in spite of infusion of air.

It has been found that use of surfactants of the invention results infine-celled phenolic foams with a high closed cell content, a lowinitial k-factor and a low k drift value.

Surfactants of the present invention are also useful in the preparationof polyisocyanurate foams and polyurethane foams. The surfactantgenerally comprises from 0.05 to 4, and preferably comprises from 0.1 to2, weight percent of the foam-forming composition.

In the broadest aspects of the present invention, any organicpolyisocyanate can be employed in the preparation of the foams of thepresent invention. The organic polyisocyanates which can be used includearomatic, aliphatic and cycloaliphatic polyisocyanates and combinationsthereof. Representative of these types are the diisocyanates such asm-phenylene diisocyanate, toluene-2,4-diisocyanate,toluene-2,6-diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate,hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate,cyclohexane-1,4-diisocyanate, hexahydrotoluene 2,4- and2,6-diisocyanate, naphthalene-1,5-diisocyanate,diphenylmethane-4,4'-diisocyanate, 4,4'-diphenylenediisocyanate,3,3'-dimethoxy-4,4'-biphenyldiisocyanate,3,3'-dimethyl-4,4'-biphenyldiisocyanate, and3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; the triisocyanates suchas 4,4',4"-triphenylmethanetriisocyanate, polymethylenepolyphenylisocyanate, toluene-2,4,6-triisocyanate; and the tetraisocyanates suchas 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate. Especiallyuseful are polymethylenepolyphenyl isocyanates. These isocyanates areprepared by conventional methods known in the art such as thephosgenation of the corresponding organic amine.

The polyols which can be employed in the preparation of the polyurethanefoam compositions include, for example, monomeric polyols, such asethylene glycol, the oxyalkylene adducts of polyol bases wherein theoxyalkylene portion is derived from a monomeric unit such as ethyleneoxide, propylene oxide, butylene oxide and mixtures thereof. The polyolinitiators include ethylene glycol, 1,2-propylene glycol, 1,3-propyleneglycol, 1,2-butanediol, 1,4-butanediol, hexanetriol, glycerol,trimethylolpropane, triethylolpropane, pentaerythritol, sorbitol,sucrose, toluene diamine and bisphenol A, polyethers such aspolyethylene ether glycols, polypropylene ether glycols,polytetramethylene ether glycols, and alkylene oxide adducts ofpolyhydric alcohols including those listed above; hydroxy terminatedtertiary amines of the formula: ##STR10## wherein R⁶ is an alkyleneradical containing at least 2 to 6 carbon atoms and E is apolyoxyalkylene chain; amine based polyethers of the formula: ##STR11##wherein E is a polyoxyalkylene chain and Y is selected from the groupconsisting of alkyl, hydroxyalkyl and EH; alkylene oxide adducts ofacids of phosphorus such as the adducts prepared by the reaction ofphosphoric acid and ethylene oxide, phosphoric acid and propylene oxide,phosphorus acid and propylene oxide, phosphonic acid and ethylene oxide,phosphinic acid and butylene oxide, polyphosphoric acid and propyleneoxide and phosphonic acid and styrene oxide.

Typical polyether polyols include polyoxyethylene glycol,polyoxypropylene glycol, polyoxybutylene glycol, polytetramethyleneglycol, block copolymers, for example, combinations of polyoxypropyleneand polyoxyethylene glycols, poly-1,2-oxybutylene and polyoxyethyleneglycols, and poly-1,4-oxybutylene and polyoxyethylene glycols, andrandom copolymer glycols prepared from blends or sequential addition oftwo or more alkylene oxides. Also adducts of the above withtrimethylolpropane, glycerine and hexanetriol as well as thepolyoxypropylene adducts of higher polyols such as pentaerythritol andsorbitol may be employed. Thus, the polyether polyols which can beemployed in the present invention include oxyalkylene polymers whichhave an oxygen/carbon ratio from about 1:2 to 1:4 and preferably anoxygen carbon atom ratio from about 1:2.8 to 1:4 and from about 2 to 6terminal hydroxyl groups, preferably about 2 to 4 terminal hydroxylgroups. The polyether polyols generally have an average equivalentweight from about 80 to 10,000 and preferably have an average equivalentweight from about 100 to about 6000. Polyoxypropylene glycols havingmolecular weights from about 200 to about 4000 corresponding toequivalent weights from about 100 to 2000 and mixtures thereof areparticularly useful as polyol reactants. Polyol blends such as a mixtureof high molecular weight polyether polyols with lower molecular weightpolyether polyols or monomeric polyols can also be employed.

Any suitable hydroxy terminated polyester may also be used. These can beobtained from the reaction of polycarboxylic acids and polyhydricalcohols. Such suitable polycarboxylic acids may be oxalic acid, malonicacid, succinic acid, glutaric acid, adipic acid, pimelic acid, subericacid, azelaic acid, sebacic acid, basillic acid, thapsic acid, maleicacid, fumaric acid, glutaconic acid, isophthalic acid and terephthalicacid. Suitable polyhydric alcohols include the following: ethyleneglycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol,1,3-butylene glycol, 1,4-butylene glycol, 1,3-pentanediol,1,4-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-hexanediol,glycerol, trimethylolpropane, trimethylolethane, hexane 1,2,6-triol,α-methylglucoside, pentaerythritol, sorbitol, sucrose, and compoundsderived from phenols such as 2,2-bis(4-hydroxyphenol)propane.

In addition to the above hydroxy-containing compounds, other compoundswhich may be employed include graft polyols. These polyols are preparedby the in situ polymerization product of a vinyl monomer in a reactivepolyol medium and in the presence of a free radical initiator. Thereaction is generally carried out at a temperature ranging from about40° C. to 150° C.

The polyurethane foams are prepared by reacting the polyol andpolyisocyanate on an essentially 1:1 to 1:1.2 equivalent basis. Theorganic polyisocyanate is mixed together with the desired polyol,surfactant, catalyst and blowing agent at temperatures ranging fromabout 0° C. to 150° C.

Any blowing agent typically employed in similar prior art foam productscontaining polyisocyanurate and/or polyurethane linkages can be employedin the compositions of the present invention. In general, these blowingagents are liquids having a boiling point between minus 50° C. and plus100° C. and preferably between 0° C. and 50° C. The blowing agents andamounts thereof described above as useful in connection with thephenolic foams may also be utilized in the polyisocyanurate andpolyurethane foams.

Suitable catalysts for the foam preparations include dibutyltindilaurate, dibutyltin diacetate, stannous octoate, lead octoate, andcobalt naphthenate. The catalysts generally comprise from 0.1 to 20 andpreferably from 0.3 to 10, weight percent of the total composition.

Other additives may also be included in the foam formulations. Includedare flame retardants, such as tris(2-chloroethyl)-phosphate, andadditional surfactants, such as the silicone surfactants, e.g.,alkylpolysiloxanes and polyalkylsiloxanes. Examples of such additionalsurfactants are the polydimethylsiloxane-polyoxyalkylene blockcopolymers available from the Union Carbide Corporation under thetradenames "L-5420" and "L-5340" and from the Dow Corning Corporationunder the tradename "DC-193."

In a preferred rigid foam of the invention containing polyisocyanuratelinkages, the organic polyisocyanate is polymethylenepolyphenylisocyanate. The polymethylene polyphenylisocyanates desirablyhave a functionality of at least 2.1 and preferably 2.5 to 3.8. Thesepreferred polymethylene polyphenylisocyanates generally have anequivalent weight between 120 and 180 and preferably have an equivalentweight between 130 and 145. The friability of foams made with thesepolyisocyanates is desirably less than 30%, preferably less than 20%.

A preferred subclass of polymethylene polyphenylisocyanates especiallyuseful in the present invention are a mixture of those of Formula XII:##STR12## wherein n is an integer from 0 to 8 and wherein the mixturehas the above-described functionality and equivalent weight. Thismixture should have a viscosity between 100 and 4,000 and preferably 250to 2500 centipoises measured at 25° C. in order to be practical for usein the present invention.

Examples of suitable polymethylene polyphenylisocyanates useful in thepresent invention include those of Formula XII, wherein n is 1 as wellas mixtures wherein n can have any value from 0 to 8 as long as themixture has the specified equivalent weight. One such mixture has 40weight percent of n=0, 22 weight percent of n=1, 12 weight percent ofn=2, and 26 weight percent of n=3 to about 8. The preferredpolymethylene polyphenyl isocyanates are described in U.S. applicationSer. No. 322,843 filed Jan. 11, 1973 now abandoned. The synthesis ofpolymethylene polyphenylisocyanates is described in Seeger et al., U.S.Pat. No. 2,683,730 and in Powers U.S. Pat. No. 3,526,652 at Column 3,Lines 6-21. It should, therefore, be understood that the polymethylenepolyphenylisocyanate available on the market under the tradenames ofPAPI-20 (Upjohn) and E-418 (Mobay) can successfully be employed withinthe spirit and scope of the present invention.

In the broadest aspects of the present invention, any diol having a lowequivalent weight, which is generally between 30 and 100, and preferablybetween 30 and 70, and having two hydroxyl groups which pass theZerewitinoff Test, can be employed to react with the polymethylenepolyphenylisocyanates described in the three immediately precedingparagraphs to produce preferred rigid foams of the invention. Triols andhigher polyols can be admixed with these diols in minor amountsgenerally less than 40 percent provided the equivalent weight of themixture is within the specified range. The preferred diols are those ofFormula XIII:

    HO--R.sup.7 --OH                                           (XIII)

wherein R⁷ is selected from the group consisting of lower alkylene andlower alkoxyalkylene with at least two carbon atoms. Examples ofsuitable diols include, among others, ethylene glycol, 1,2-propanediol,1,3-propanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol,dimethylol dicyclopentadiene, 1,3-cyclohexanediol, and1,4-cyclohexanediol. Diethylene glycol is preferred since it gives acore of minimum friability and optimum facer sheet adhesion.

In order to ensure complete reaction, the polymethylenepolyphenylisocyanate and the diol are generally mixed in an equivalentratio of 2:1 to 6:1 and preferably 3:1 to 5:1. In ranges outside theseproportions the reaction yields a product having undesirable physicalcharacteristics. At higher ratios the product has an undesirably highfriability. At lower ratios the product has an undesirably highflammability.

In the preparation of these rigid foams, any catalysts known to catalyzethe trimerization of isocyanates to form isocyanurates can be employedas long as they give cream times of 15 to 30 seconds and firm times of25 to 60 seconds. One preferred type of catalyst is a mixture ofequivalent amounts of 2,4,6-tris(dimethylaminomethyl)phenol andpotassium-2-ethyl hexoate, the synthesis and use of which is describedin U.S. Pat. No. 4,169,921, issued Oct. 2, 1979. Another catalyst systemis that employing an epoxide, an N-substituted aziridine, and a tertiaryamine. The synthesis and use of such a catalyst is described in U.S.application Ser. No. 251,279 filed May 8, 1972, now U.S. Pat. No.3,799,896.

Referring now to the drawings, and in particular to FIG. 1, there isshown schematically an apparatus 10 suitable for use in connection withthe present invention. The apparatus 10 comprises an isocyanate tank 11,a polyol tank 12, and a catalyst tank 13, each respectively connected tooutlet lines 14, 15, and 16. The lines 14, 15, and 16 form the inlet tometering pumps 17, 18, and 19. The pumps 17, 18, and 19 dischargerespectively through lines 20, 21, and 22 which are in turn respectivelyconnected to flexible lines 23, 24, and 25. The flexible lines 23, 24,and 25 discharge to mixing head 29. The apparatus 10 is also providedwith a roll 30 of lower substrate material and a roll 31 of uppersubstrate material. The apparatus 10 is also provided with meteringrolls 32 and 33, and an oven 35 provided with vents 36, 36' for blowinghot air. The apparatus 10 is also provided with pull rolls 38, 39 andcutting knife 44.

In operation, the isocyanate tank 11 is charged with the organicpolyisocyanate admixed with the blowing agent and the surfactant, andthe polyol tank 12 is charged with the polyol, and the catalyst tank 13is charged with the catalyst composition. The speeds of the pumps 17,18, and 19 are adjusted to give the desired ratios of the ingredients inthe tanks 11, 12, and 13. These ingredients pass respectively throughlines 20, 21, and 22 as well as lines 23, 24 and 25, whereupon they aremixed in the mixing head 29 and discharged therefrom. Alternatively,lines 21 and 22 can be combined prior to the mixing head. The pull rolls38, 39 each of which has a flexible outer sheath 40, 41 are caused torotate in the direction of the arrows by a power source (not shown). Byvirtue of rotation of the pull rolls 38, 39 lower substrate material ispulled from the roll 30, whereas upper substrate material is pulled fromthe roll 31. The substrate material passes over idler rollers such asidler rollers 46 and 47 and is directed to the nip between meteringrolls 32, 33. The mixing head 29 is caused to move back and forth, i.e.out of the plane of the paper by virtue of its mounting on reversiblemechanism 49. In this manner, an even amount of material can bemaintained upstream of the nip between the metering rolls 32, 33. Thecomposite structure at this point now comprising a lower substrate 51,an upper substrate 52 on either side of a core 53, now passes into theoven 35. While in the oven 35 the core expands under the influence ofheat added by the hot air from vents 36, 36' and due to the heatgenerated in the exothermic reaction between the polyol, the diol, andthe isocyanate in the presence of the catalyst. The temperature withinthe oven is controlled by varying the temperature of the hot air fromvents 36, 36', in order to insure that the temperature within the oven35 is maintained within the herein described limits. The compositestructure 55 then leaves the oven 35, passes between the nip of the pullrolls 38, 39 and is cut by knife 44 into individual panels 57, 57'.

Numerous modifications to the apparatus 10 will be immediately apparentto those skilled in the art. For example, the tanks 11, 12 and 13 can beprovided with refrigeration means in order to maintain the reactants atsubambient temperatures.

Referring to FIG. 2 of the drawings, there is shown a laminated buildingpanel 60 of the invention. The building panel 60 comprises a singlefacing sheet 61 having thereon a cellular material 62 of the presentinvention. FIG. 3 shows a building panel 70 having two facing sheets 71and 72 on either side of a cellular material 73.

Any facing sheet previously employed to produce building panels can beemployed in the present invention. Examples of suitable facing sheetsinclude, among others, those of kraft paper, aluminum, and asphaltimpregnated felts, as well as laminates of two or more of the above.

The foam materials of the invention can also be used, with or without afacer(s), for pipe insulation.

The foam materials of the invention can contain various reinforcementmaterials, such as a quantity of glass fibers, as described in U.S. Pat.No. 4,118,533, the disclosure of which is hereby incorporated byreference.

The invention is further illustrated by the following examples in whichall parts and percentages are by weight unless otherwise indicated.These non-limiting examples are illustrative of certain embodimentsdesigned to teach those skilled in the art how to practice the inventionand to represent the best mode contemplated for carrying out theinvention.

EXAMPLE 1 Preparation of Dipentyl Maleate, Dihexyl Maleate and DioleylMaleate

Dipentyl maleate (DPM), dihexyl maleate (DHM), and dioleyl maleate(DOLM) were prepared according to a procedure given in the literature.*To a 1 liter, 3-necked round bottom flask equipped with an overheadstirrer and a Dean Stark trap were added 350 ml of benzene, maleicanhydride (87 g), the alcohol (1.65 moles of either pentanol, hexanol,or oleyl alcohol) and p-toluene sulfonic acid (1.2 g). The mixture washeated to reflux, under nitrogen, until water was no longer collected(˜17 ml water collected or approximately 75% conversion). The solvent,water and excess alcohol were removed in vacuo. The residue wasdissolved in ethyl acetate or dichloromethane and extracted with water(˜300 ml), 5% NaHCO₃ (˜300 ml), dried over MgSO₄, filtered and thesolvent evaporated in vacuo.

DPM was obtained in approximately 70% yield: Calculated analysis for C₁₄H₂₄ O₄ : C, 65.60; H, 9.44. Found: C, 65.54; H, 9.31.

DHM was obtained in 72% yield: Calculated analysis for C₁₆ H₂₄ O₄ : C,67.57; H, 9.92. Found: C, 67.09; H, 9.50.

DOLM was obtained in 70% yield: Calculated analysis for C₄₀ H₇₂ O₄ : C,77.86; H, 11.76. Found: C, 78.41; H, 11.96.

EXAMPLE 2 Preparation of Tetronic Polyol-Maleate Diester Surfactants

This example illustrates the preparation of various Tetronicpolyol-maleate diester surfactants.

To a 500 ml resin kettle equipped with an overhead stirrer were added200 g of ethoxylated propoxylated ethylene diamine (Tetronic 704) and0.33 g of ferrocene. A nitrogen stream was provided through the resinkettle. A solution containing 6 g of tert.-butyl perbenzoate dissolvedin 34 g of dibutyl maleate was added slowly over two hours to the polyolfrom an addition funnel. During the addition, the reaction mixture wasmaintained at 100° C. After the addition, the temperature of thereaction mixture was increased to 140° C. for one hour and then allowedto cool to room temperature. Acetic anhydride (17 g) was next added tothe reaction mixture. This addition corresponds to the amount of aceticanhydride needed to cap the polyol, as determined from the polyolhydroxyl number. The mixture was heated to 100° C. for two hours andthen cooled to room temperature to produce a polyol-maleate diestersurfactant in the form of a viscous liquid (Surfactant No. 1 of Table Ibelow). (The acetic anhydride caps the hydroxyl end groups of the polyolwith acetate groups.) Residual dibutyl maleate, according to GLC, was1.4% (90% conversion).

The above alkoxylated diamine used in the preparation of Surfactant No.1 has a molecular weight of 5500, has a weight ratio of ethylene oxideto propylene oxide of 40:60, and is available from the BASF WyandotteCorporation, Wyandotte, Mich., U.S.A., under the tradename "TETRONIC704."

Surfactant Nos. 2-7 of Table I below were prepared in a similar manneremploying Tetronic 704 (200 g), ferrocene and tert.-butyl perbenzoate atthe same level, i.e., 0.13 phr and 2.4 phr, respectively, and themaleate diesters listed in the table in the amounts designated therein.

                  TABLE I                                                         ______________________________________                                        TETRONIC 704-MALEATE DIESTER SURFACTANTS                                      SURFACTANT                                                                         Physical    DIESTER UTILIZED                                             No.  Form        Name            Weight (g)                                   ______________________________________                                        1    liquid      Dibutyl Maleate 34                                           2    liquid      Dipentyl Maleate*                                                                             34                                           3    liquid      Dihexyl Maleate*                                                                              34                                           4    liquid      Dioctyl Maleate 34                                           5    liquid      Dioctyl Maleate 50                                           6    liquid      Ditridecyl Maleate                                                                            34                                           7    liquid      Ditridecyl Maleate                                                                            50                                           ______________________________________                                         *Dipentyl and dihexyl maleates were prepared according to the procedure o     Example 1.                                                               

EXAMPLE 3

This example illustrates the synthesis of a phenolic polymer useful inthe present invention employing a molar ratio of phenol to o-cresol of2:1.

The following quantities of the following ingredients were combined asindicated.

    ______________________________________                                                             Amount                                                   Item    Ingredient         grams   moles                                      ______________________________________                                        A       o-cresol           10,580  98                                         B       paraformaldehyde (93.6%)                                                                         4,743   148                                        C       sodium hydroxide (50%)                                                                           295     3.69                                       D       phenol             18,428  196                                        E       paraformaldehyde (93.6%)                                                                         7,917   247                                        F       glacial acetic acid                                                                              225     3.75                                       ______________________________________                                    

Items A and B are charged to a reaction vessel. Item C is added over aperiod of fifteen minutes, the temperature rises to 100° C. due to anexothermic reaction and is maintained at that level for 1.5 hours. ItemsD and E are then added and the temperature maintained at 80° C. for fourand one-half hours. Item F is then added and the contents of thereaction are termed Resin B.

Resin B has a viscosity at 25° C. of 16,500 cps, a free phenol contentof 9%, and a free water content of 8.5%, a free formaldehyde content of0.5%, and a free o-cresol content of less than 0.1%.

EXAMPLE 4

This example illustrates the synthesis of a foaming catalyst useful inthe present invention.

The following quantities of the following ingredients are combined asindicated to produce Catalyst A:

    ______________________________________                                        Ingredients        Quantity                                                   Item          Name     grams                                                  ______________________________________                                        A             Ultra TX 667                                                    B             water    333                                                    ______________________________________                                    

Items A and B are mixed. The resultant composition is termed Catalyst A.Ultra TX is a mixture of equal parts by weight of p-toluene sulfonicacid and xylene sulfonic acids available from the Witco ChemicalCompany.

EXAMPLE 5

This example illustrates the synthesis of phenolic foams based on 2:1phenol:o-cresol resoles utilizing as surfactant the polyol-maleatediester products of Example 2.

In each foam synthesis, the following quantities of the followingingredients were combined as indicated:

    ______________________________________                                        Item       Ingredient      grams                                              ______________________________________                                        A          Resin B of Example 3                                                                          300                                                B          CFCl.sub.3      22.5                                               C          CCl.sub.2 FCF.sub.2 Cl                                                                        22.5                                               D          Surfactant (See below)                                                                        15                                                 E          Catalyst A of Example 4                                                                       40                                                 ______________________________________                                    

Items A through E were mixed at 15° C. in an open vessel for 15 seconds.The mixture was then poured into a square paper box twelve inches bytwelve inches by five inches tall. A foaming reaction ensued. After aperiod of about 240-300 seconds the material was rigid. The box andcontents were placed in an oven at 55° to 75° C. for a period of tenminutes to one hour.

The characteristics of the phenolic foams synthesized in accordance withthe above procedure are shown in the following Table II.

                                      TABLE II                                    __________________________________________________________________________    FOAM EVALUATION OF SURFACTANTS                                                                        FRIABILITY                                            PHENOLIC                                                                             SURFACTANT NO..sup.a                                                                     DENSITY                                                                             % wt. loss,                                                                           K-FACTOR.sup.c AFTER                          FOAM   (Maleate Diester).sup.b                                                                  pcf   10 min. 1 day                                                                             7 days                                                                            14 days                                                                           CELL QUALITY                      __________________________________________________________________________    A      1 (Dibutyl Maleate)                                                                            high    .263        Very coarse-celled                B      2 (Dipentyl Maleate)                                                                     1.9   39      .237        Coarse-celled                                                     .198                                                                          .249                                          C      3 (Dihexyl Maleate)                                                                      1.56  25      .219        Slightly coarse-                                                  .300        celled                            D      4 (Dioctyl Maleate)                                                                      2.3   12      .117                                                                              .124                                                                              .121                                                                              Fine-celled                                                       .120                                                                              .120                                                                              .122                                  E      5 (Dioctyl Maleate)                                                                      2.6   11      .119                                                                              .124                                                                              .122                                                                              Fine-celled                                                       .121                                                                              .129                                                                              .133                                  F      6 (Ditridecyl Maleate)                                                                   2.9    8      .123                                                                              .121                                                                              .124                                                                              Fine-celled                       G      7 (Ditridecyl Maleate)                                                                   2.35  11      .121                                                                              .122                                                                              .122                                                                              Fine-celled                                                       .121                                                                              .124                                                                              .129                                  __________________________________________________________________________     .sup.a Of Example 2.                                                          .sup.b Maleate diester used in preparing the surfactant.                       .sup.c Units = Btuin/hr-ft.sup.2°F.                              

The Table II results show that the quality of the phenolic foam improveswith an increase in the size of the hydrocarbon group on the maleatediester used in preparing the foam surfactant. Comparison of theproperties of Foam C with those of Foams D and E reveals a particularlysignificant improvement when the hydrocarbon group increases from hexylto octyl.

EXAMPLE 6 Preparation of Pluronic Polyol-Maleate Diester Surfactants

This example illustrates the synthesis of surfactants from maleatediesters and "Pluronic" polyols (available from BASF WyandotteCorporation).

A. Molecular Weight and Ethylene Oxide Content of Pluronics

The molecular weight and ethylene oxide content of the Pluronic polyolsutilized in the preparation of the surfactants of this example are shownin the following Table III. For comparison, the molecular weight andethylene oxide content of the Tetronic 704 adduct employed in Example 2are also shown in Table III.

                  TABLE III                                                       ______________________________________                                        MOLECULAR WEIGHT AND ETHYLENE OXIDE                                           CONTENT OF PLURONICS                                                          POLYOL      MOLECULAR    WEIGHT %                                             UTILIZED    WEIGHT       ETHYLENE OXIDE                                       ______________________________________                                        Pluronic L31                                                                              1100         10                                                   Pluronic L35                                                                              1900         50                                                   Pluronic L42                                                                              1630         20                                                   Pluronic L43                                                                              1850         30                                                   Pluronic L44                                                                              2200         40                                                   Pluronic L63                                                                              2650         30                                                   Pluronic L64                                                                              2900         40                                                   Pluronic P65                                                                              3400         50                                                   Pluronic F68                                                                              8350         80                                                   Pluronic L72                                                                              2750         20                                                   Pluronic P84                                                                              4200         40                                                   Pluronic P85                                                                              4600         50                                                   Pluronic F87                                                                              7700         70                                                   Pluronic P104                                                                             5850         40                                                   Pluronic L121                                                                             4400         10                                                   Pluronic L122                                                                             5000         20                                                   Pluronic P123                                                                             5750         30                                                   Tetronic 704                                                                              5500         40                                                   ______________________________________                                    

The letters L, P, and F before the numbers in the designation of eachPluronic polyol of Table III represent the physical form of the polyol:liquid, paste or flaky solid. The last digit of the numbers representsthe approximate weight percent of ethylene oxide contained in the polyoldivided by 10.

B. Method of Preparation of Surfactants

A 500 ml resin kettle equipped with an overhead stirrer was charged witha mixture of 200 g of Pluronic L31 (listed in Table III above) and 0.33g of ferrocene. While stirring the mixture under nitrogen at atemperature of 90° C., 34 g of dioctyl maleate were added from anaddition funnel over two hours. 6 g of tert.-butyl perbenzoate wasdissolved in the dioctyl maleate prior to the addition. Following theaddition, the temperature was increased to 140° C. for one hour. Themixture was then cooled to room temperature and the appropriate amountof acetic anhydride (determined from the polyol's hydroxyl number) wasadded to cap the polyol. The temperature was next increased to 100° C.for one hour, after which the surfactant product was cooled to roomtemperature to yield a viscous liquid product (Surfactant No. 8 of TableIV below).

Surfactant Nos. 9-34 of Table IV below were each prepared in a similarmanner employing the Pluronic polyol (200 g) listed in the table,ferrocene and tert.-butyl perbenzoate at the same level, i.e., 0.13 phrand 2.4 phr, respectively, and the maleate diester listed in the tablein the amount designated therein.

                  TABLE IV                                                        ______________________________________                                        PLURONIC-MALEATE DIESTER SURFACTANTS                                                    PLURONIC DIESTER UTILIZED                                           SURFACTANT  POLYOL               Weight                                       No.  Physical Form                                                                            UTILIZED   Name        (g)                                    ______________________________________                                         8   viscous liquid                                                                           Pluronic L31                                                                             Dioctyl Maleate                                                                           34                                      9   viscous liquid                                                                           Pluronic L35                                                                             Dioctyl Maleate                                                                           34                                     10   viscous liquid                                                                           Pluronic L42                                                                             Dioctyl Maleate                                                                           34                                     11   viscous liquid                                                                           Pluronic L43                                                                             Dioctyl Maleate                                                                           34                                     12   viscous liquid                                                                           Pluronic L44                                                                             Dioctyl Maleate                                                                           34                                     13   viscous liquid                                                                           Pluronic L63                                                                             Dioctyl Maleate                                                                           34                                     14   viscous liquid                                                                           Pluronic L64                                                                             Dioctyl Maleate                                                                           34                                     15   viscous liquid                                                                           Pluronic L64                                                                             Dioctyl Maleate                                                                           50                                     16   paste      Pluronic P65                                                                             Dioctyl Maleate                                                                           50                                     17   paste      Pluronic F68                                                                             Dioctyl Maleate                                                                           50                                     18   viscous liquid                                                                           Pluronic L72                                                                             Dioctyl Maleate                                                                           50                                     19   paste      Pluronic P84                                                                             Dioctyl Maleate                                                                           50                                     20   paste      Pluronic P85                                                                             Dioctyl Maleate                                                                           50                                     21   paste      Pluronic F87                                                                             Dioctyl Maleate                                                                           50                                     22   paste      Pluronic P104                                                                            Dioctyl Maleate                                                                           34                                     23   viscous liquid                                                                           Pluronic L121                                                                            Dioctyl Maleate                                                                           34                                     24   viscous liquid                                                                           Pluronic L122                                                                            Dioctyl Maleate                                                                           50                                     25   paste      Pluronic P123                                                                            Dioctyl Maleate                                                                           50                                     26   viscous liquid                                                                           Pluronic L44                                                                             Ditridecyl Maleate                                                                        34                                     27   viscous liquid                                                                           Pluronic L63                                                                             Ditridecyl Maleate                                                                        34                                     28   viscous liquid                                                                           Pluronic L64                                                                             Ditridecyl Maleate                                                                        34                                     29   viscous liquid                                                                           Pluronic L64                                                                             Ditridecyl Maleate                                                                        50                                     30   paste      Pluronic P65                                                                             Ditridecyl Maleate                                                                        50                                     31   paste      Pluronic F68                                                                             Ditridecyl Maleate                                                                        50                                     32   paste      Pluronic P84                                                                             Ditridecyl Maleate                                                                        50                                     33   paste      Pluronic P85                                                                             Ditridecyl Maleate                                                                        50                                     34   paste      Pluronic P123                                                                            Ditridecyl Maleate                                                                        50                                     ______________________________________                                    

EXAMPLE 7

This example illustrates the synthesis of phenolic foams based on 2:1phenol:o-cresol resoles utilizing as surfactant various polyol-maleatediester products of Example 6.

Each foam synthesis was performed according to the procedure of Example5 utilizing the ingredients and amounts of the same described in saidexample, but replacing the surfactants of Example 5 by the surfactantslisted in Table V below. As in Example 5, 15 g of surfactant wereemployed in each foam synthesis. The characteristics of the phenolicfoams produced are shown in the following Table V.

                                      TABLE V                                     __________________________________________________________________________    FOAM EVALUATION OF SURFACTANTS                                                                        FRIABILITY                                            PHENOLIC          DENSITY                                                                             % wt. loss,                                                                           K-FACTOR.sup.b AFTER                          FOAM   SURFACTANT NO..sup.a                                                                     pcf   10 min. 1 day                                                                             7 days                                                                            14 days                                                                           28 days                                                                           CELL QUALITY                  __________________________________________________________________________    A      12         2.20  13      .138                                                                              .204        fine-celled                                                   .130                                                                              .145                                      B      13         2.45  12      .119                                                                              .175                                                                              .192    fine-celled                                                   .122                                                                              .161                                                                              .182                                  C      14         2.45  12      .123                                                                              .136                                                                              .142    fine-celled                                                   .122                                                                              .173                                                                              .192                                  D      15         2.10  13      .150                                                                              .225        fine-celled                                                   .162                                                                              .222                                      E      16         2.40  12      .116                                                                              .153                                                                              .171    fine-celled                                                   .117                                                                              .152                                                                              .170                                  F      17         1.65   9      .119                                                                              .126                                                                              .113                                                                              .114                                                                              fine-celled                                                   .120                                          G      19         2.31  11      .115                                                                              .119                                                                              .115                                                                              .112                                                                              fine-celled                                                   .121                                                                              .114                                                                              .119                                                                              .121                              H      20         2.7   13      .112                                                                              .113                                                                              .115                                                                              .116                                                                              fine-celled                                                   .117                                                                              .121                                                                              .124                                                                              .123                              I      25         2.58  13      .116                                                                              .139                                                                              .154                                                                              .173                                                                              fine-celled                                                   .114                                                                              .118                                                                              .121                                  J      26         2.20  12      .142                                                                              .222        fine-celled                                                   .157                                                                              .189                                      K      27         2.70  14      .120                                                                              .138                                                                              .147    fine-celled                                                   .130                                                                              .142                                                                              .142                                  L      28         2.60  13      .123                                                                              .133                                                                              .134    fine-celled                                                   .120                                                                              .129                                                                              .133                                  M      29         2.60  13      .119                                                                              .123                                                                              .127    fine-celled                                                   .122                                                                              .144                                                                              .161                                  N      30         2.68  12      .117                                                                              .125                                                                              .125    fine-celled                                                   .117                                                                              .124                                                                              .123                                  O      31         2.56  11      .114                                                                              .119                                                                              .116    fine-celled                                                   .114                                                                              .121                                                                              .122                                  P      32         1.8   14      .118                                                                              .128                                                                              .131                                                                              .137                                                                              fine-celled                   Q      33         1.95  13      .119                                                                              .126                                                                              .121    fine-celled                                                   .122                                                                              .129                                                                              .136                                  R      34         1.84  13      .120                                                                              .128                                                                              .130    fine-celled                   __________________________________________________________________________     .sup.a Of Example 6. Dioctyl maleate was used in preparing Surfactant Nos     12 to 25, and ditridecyl maleate was used in preparing Surfactant Nos. 26     to 34.                                                                        .sup.b Units = Btuin/hr-ft.sup.2°F.                               

The Table V results show that of those phenolic foams made with thePluronic polyol-dioctyl maleate surfactants, the best quality foams wereobtained utilizing surfactants, wherein the molecular weight of thePluronic polyol was 4200 (Surfactant No. 19 made with Pluronic P84) ormore. The results also show that the Pluronic polyol-ditridecyl maleatesurfactants as a group surpassed the Pluronic-dioctyl maleatesurfactants in phenolic foam stabilization capacity.

EXAMPLE 8

This example illustrates the synthesis of a phenolic polymer useful inthe present invention employing a molar ratio of phenol to ortho cresolof 4:1.

The following quantities of the following ingredients were combined asindicated.

    ______________________________________                                                             Amount                                                   Item Ingredient            grams   moles                                      ______________________________________                                        A    o-cresol              6,901   63.9                                       B    paraformaldehyde (93.5% HCHO)                                                                       3,133   97.7                                       C    sodium hydroxide (50% NaOH)                                                                         215     2.69                                       D    phenol                24,025  255.5                                      E    paraformaldehyde (93.5% HCHO)                                                                       11,350  354.1                                      F    sodium hydroxide (50% NaOH)                                                                         215     2.69                                       G    glacial acetic acid   350     5.8                                        ______________________________________                                    

Items A and B were charged to a reaction vessel. Item C was added over aperiod of fifteen minutes, the temperature rose due to the exothermicreaction to 100° C. and was maintained at that level for 1.5 hours.Items D, E, and F are then added and the temperature maintained at 80°C. for 5 hours. Item G was then added and the contents of the reactionvessel are termed Resin C.

Resin C has a viscosity at 25° C. of 22,000 cps, a free phenol contentof 9%, and a free water content of 10.9%, a free formaldehyde content of1.1%, and a free o-cresol content of less than 0.1%.

EXAMPLE 9

This example illustrates the synthesis of a phenolic foam based on a 4:1phenol:o-cresol resole utilizing as surfactant the PluronicP123-ditridecyl maleate surfactant (Surfactant No. 34) of Example 6.

In the foam synthesis, the following quantities of the followingingredients were combined as indicated:

    ______________________________________                                                                      Quantity                                        Item Ingredient               grams                                           ______________________________________                                        A    Resin C of Example 8     300                                             B    CFCl.sub.3               22.5                                            C    CFCl.sub.2 CF.sub.2 Cl   22.5                                            D    Pluronic P123 - ditridecyl maleate surfactant                                                          15                                              E    Catalyst A of Example 4  40                                              ______________________________________                                    

Items A through E were mixed at 15° C. in an open vessel for 15-20seconds. The mixture was then poured into a square paper box twelveinches by twelve inches by five inches tall. A foaming reaction ensued.After a period of 300-600 seconds the material was rigid. The box andcontents were placed in an oven at 55° to 75° C. for a period of tenminutes to one hour.

The foam synthesis had a cream time of 140 sec. and a firm time of 10min. The k-factor (Btu-in/hr-ft² -°F.) of the resulting foam was asfollows:

    ______________________________________                                        k-factor after                                                                1 day     7 days  14 days     28 days                                                                             56 days                                   ______________________________________                                        .116      .115    .116        .115  .124                                      ______________________________________                                    

EXAMPLE 10 Ethoxylated Castor Oil--Dioctyl Maleate Surfactants inPhenolic Foams A. Method of Preparation of Surfactants

A series of surfactants (Surfactant Nos. 35 to 39 of Table VI below)were prepared by reacting dioctyl maleate with each of a group ofethoxylated castor oils having different ethylene oxide (EO) contents.The EO-castor oils utilized contained 20, 25, 36, 40 or 54 moles of EOper mole of castor oil and are each sold by Sellers Chemical Corporationas Flo Mo (moles EO per mole oil) C, such as Flo Mo. 20C for the productcontaining 20 moles EO per mole oil. Each surfactant was preparedaccording to the procedure of Example 6 utilizing the ingredients andamounts of the same described in said example, but replacing thePluronics of Example 6 by the ethoxylated castor oils listed in Table VIbelow and employing 34 g of dioctyl maleate in each surfactantpreparation.

B. Foam Evaluation of Surfactants

The above-described ethoxylated castor oil-dioctyl maleate surfactantswere employed in the synthesis of phenolic foams based on 2:1phenol:o-cresol resoles. Each foam synthesis was performed according tothe procedure of Example 5 utilizing the ingredients and amounts of thesame described in said example, but replacing the surfactants of Example5 by the ethoxylated castor oil-dioctyl maleate surfactants listed inTable VI. The characteristics of the phenolic foams produced are shownin the following Table VI.

                                      TABLE VI                                    __________________________________________________________________________    EVALUATION OF EO-CASTOR OIL-DIOCTYL                                           MALEATE SURFACTANTS IN RESOLE B FOAMS                                                                     RESOLE B FOAM                                     SURFACTANT            RESIN B.sup.1                                                                       k-factor.sup.2 after                                     Physical                                                                             EO-Castor Oil                                                                         Viscosity                                                                           1  7  14 28 56 120                                Foam                                                                              No.                                                                              Form   Utilized                                                                              25° C. (cps)                                                                 day                                                                              days                                                                             days                                                                             days                                                                             days                                                                             days                               __________________________________________________________________________    A   35 viscous liquid                                                                       Flo Mo 20 C                                                                           26,800                                                                              .138                                                                             .235                                           B   36 viscous liquid                                                                       Flo Mo 25 C                                                                           26,800                                                                              .135                                                                             .191                                                                             .219                                        C   37 viscous liquid                                                                       Flo Mo 36 C                                                                           20,000                                                                              .123                                                                             .121                                                                             .128                                                                             .124                                                                             .125                                                                             .132                                                           .120                                                                             .121                                                                             .117                                                                             .118                                                                             .118                                                                             .129                               D   38 viscous liquid                                                                       Flo Mo 40 C                                                                           26,800                                                                              .132                                                                             .142                                                                             .145                                        E   39 paste  Flo Mo 54 C                                                                           26,800                                                                              .124                                                                             .123                                                                             .122                                        __________________________________________________________________________     .sup.1 Each Resin B of Table VI was prepared according to the procedure o     Example 3.                                                                    .sup.2 Units = Btuin/hr-ft.sup.2°F.                               

EXAMPLE 11 Preparation of Tetronic Polyol-Maleate Diester Surfactants

This example illustrates the preparation of a series of Tetronic polyolmaleate diester surfactants (Surfactant Nos. 40 to 47 of Table VIIbelow) utilizing Tetronic polyols (alkoxylated diamines) having variousmolecular weights and containing a weight ratio of ethylene oxide (EO)to propylene oxide (PO) of 20:80 or 40:60. These Tetronic polyols areavailable from the BASF Wyandotte Corporation, Wyandotte, Mich.

Each surfactant synthesis was performed according to the procedure ofExample 6 utilizing the ingredients and amounts of the same described insaid example, but employing, in place of the Pluronics the Tetronicspresented in the following table and employing the maleate diesters inthe quantities shown in the following table.

                  TABLE VII                                                       ______________________________________                                        PREPARATION OF TETRONIC - MALEATE DIESTER                                     SURFACTANTS                                                                   SURFAC-   TETRONIC UTILIZED MALEATE                                           TANT                        EO:PO DIESTER                                          Physical         Molecular                                                                             Weight                                                                              UTILIZED                                  No.  Form     Name    Weight  Ratio Name*  wt. (g)                            ______________________________________                                        40   liquid    702    4,000   20:80 DOM    34                                 41   liquid    704    5,500   40:60 DOM    34                                 42   liquid    704    5,500   40:60 DTDM   34                                 43   liquid   1502    9,000   20:80 DOM    34                                 44   liquid   1502    9,000   20:80 DTDM   34                                 45   liquid   1502    9,000   20:80 DTDM   50                                 46   solid    1504    12,500  40:60 DTDM   50                                 47   liquid   1502    9,000   20:80 DOLM   50                                 ______________________________________                                         *DOM = Dioctyl Maleate                                                        *DTDM = Ditridecyl Maleate                                                    *DOLM = Dioleyl Maleate                                                  

EXAMPLE 12 Preparation of Ethoxylated Castor Oil-Maleate DiesterSurfactants

To a 500 ml resin kettle equipped with an overhead stirrer were added200 g of Flo Mo 36 C (ethoxylated castor oil) and 27 g acetic anhydride.A nitrogen stream was provided through the resin kettle. After heatingthese ingredients to 100° C. for two hours, the acetic acid was strippedoff in vacuo to yield a liquid product with an acid number of less than2.0. To this capped material were added 50 g ditridecyl maleate and 6 g1,1-bis(t-butylperoxy)cyclohexane (available from Witco Chemical Companyunder the tradename USP-400P). The mixture was then heated to 110° C.for 4 hours to yield a viscous liquid surfactant of the invention(Surfactant No. 48 of Table VIII below).

Surfactant Nos. 49 and 50 of Table VIII below were prepared according tothe above procedure except that, in the synthesis of Surfactant No. 49,the maleate diester and initiator were replaced by dioctyl maleate (34g) and t-butyl perbenzoate, respectively, and acetic acid was notstripped from the reaction mixture, and, in the synthesis of SurfactantNo. 50, Flo Mo 36 C was replaced by Flo Mo 54 C.

                  TABLE VIII                                                      ______________________________________                                        ETHOXYLATED CASTOR OIL-MALEATE DIESTER                                        SURFACTANTS                                                                                             MALEATE                                             SURFACTANT                DIESTER                                                  Physical   EO-CASTOR OIL UTILIZED                                        No.  State      UTILIZED      Name     Wt. (g)                                ______________________________________                                        48   liquid     Flo Mo 36 C.sup.1                                                                           DTDM.sup.3                                                                             50                                     49   liquid     Flo Mo 36 C.sup.1                                                                           DOM.sup.2                                                                              34                                     50   paste      Flo Mo 54 C.sup.1                                                                           DTDM.sup.3                                                                             50                                     ______________________________________                                         .sup.1 See Example 10 for description of EOcastor oils used.                  .sup.2 DOM = dioctyl maleate.                                                 .sup.3 DTDM = ditridecyl maleate.                                        

EXAMPLE 13

This example illustrates the synthesis of polyisocyanurate foamsutilizing as surfactant a number of the surfactants of the presentinvention presented in Table IX below.

In each foam synthesis, the following quantities of the followingingredients were combined as indicated:

    ______________________________________                                                                     Quantity                                         Item  Ingredient             (grams)                                          ______________________________________                                        A     polymethylene polyphenyl isocyanate                                                                  277                                              B     diethylene glycol      23                                               C     2,4,6-tris (dimethylaminomethyl)                                                                     (See below)                                            phenol                                                                  D     potassium-2-ethyl hexoate                                                                            (See below)                                            (70% solution in E)                                                     E     polyoxyethylene glycol (See below)                                      F     CFCl.sub.3             55                                               G     Surfactant (See Table IX below)                                                                      2.5                                              ______________________________________                                    

A large batch of polymethylene polyphenyl isocyanate and CFCl₃ in theratio 277 parts:55 parts, respectively, was prepared by mixing togetherthe two ingredients and storing them at 0°-15° C. In each foampreparation, 332 g of the polymethylene polyphenyl isocyanate/CFCl₃mixture, at a temperature of 15° C., was poured into a reaction vessel.2.5 g of the surfactant (shown in Table IX below) and 23 g of diethyleneglycol were then added to the vessel, and all ingredients were mixed at3600 rpm for 5 seconds. The catalyst mixture (15 g) described below wasthen mixed into the contents of the vessel over a 3 second interval. Allingredients were thereafter mixed at 3600 rpm for an additional 7seconds and then poured into boxes, yielding a polyisocyanurate foam.

Various characteristics of the foams produced utilizing the catalystmixture are shown in the following Table IX under the heading "CatalyzedFoam."

The above-described foam synthesis was repeated for each of thesurfactants of Table IX, except that the catalyst mixture was not addedin these additional foam preparations. By preparing the foams withoutthe catalyst the extent of defoaming (bubble breakage) prior to andduring foam rise and the size of the foam bubbles prior to firm time canbe visually assessed. These observations for the uncatalyzed foams arepresented in Table IX below.

In the above syntheses, Item A is a polymethylene polyphenyl isocyanatehaving an equivalent weight of 138, an acidity of 0.03% HCl, and aviscosity of 2000 centipoises at 25° C. and is available from the MobayChemical Company, Pittsburgh, Pa. under the trade name MONDUR MR-200.

Item C is that supplied by the Rohm & Haas Chemical Company under thetrade name DMP-30.

Item D is employed in the form of a 70 weight % solution in thepolyoxyethylene glycol (Item E) sold by the Union Carbide Corporationunder the trade name Carbowax 200.

The catalyst mixture of Items C, D and E added in the above-describedfoam preparation is a blend of DMP-30:potassium-2-ethylhexoate:polyoxyethylene glycol in a 1:3:8 weight ratio.

                                      TABLE IX                                    __________________________________________________________________________    SURFACTANTS IN POLYISOCYANURATE FOAMS                                         SURFACTANT    UNCATALYZED                                                                              CATALYZED FOAM                                                Acetic                                                                             FOAM                 Friability                                                                           k-factor.sup.10 after                        Acid       Bubble                                                                             Cell Density                                                                            (% wt. loss,                                                                         1  7  14 28                         Foam                                                                              No.  Present.sup.1                                                                      Defoaming                                                                           Size Structure                                                                          (pcf)                                                                              10 min.)                                                                             day                                                                              days                                                                             days                                                                             days                       __________________________________________________________________________    A   25.sup.2                                                                           Yes  Some  Medium                                                                             Slightly                                                                      Coarse                                               B   40.sup.3                                                                           Yes  Significant                                                                         Large to                                                                           Slightly                                                                           1.93 40     .121                                                                             .133                                                                             .139                                              Medium                                                                             Coarse                                               C   41.sup.3                                                                           Yes  Significant                                                                         Large to                                                                           Slightly                                                                 Medium                                                                             Coarse                                               D    5.sup.4                                                                           Yes  Significant                                                                         Large to                                                                           Slightly                                                                           1.89 41     .120                                                                             .132                                                                             .138                                              Medium                                                                             Coarse                                               E    7.sup.4                                                                           Yes  Some  Medium                                                                             Slightly                                                                      Coarse                                               F   43.sup.3                                                                           Yes  Some to                                                                             Medium                                                                             Slightly                                                                           1.82 38     .120                                                                             .133                                                                             .139                                        Significant                                                                         to Small                                                                           Coarse                                               G   45.sup.3                                                                           Yes  Some  Medium                                                                             Slightly                                                                 to Small                                                                           Coarse                                               H   51.sup.5                                                                           No   Slight                                                                              Medium                                                                             Slightly                                                                 to Small                                                                           Coarse                                               I   46.sup.3                                                                           Yes  Some  Large                                                                              Slightly                                                                      Coarse                                               J   52.sup.6                                                                           No   Slight                                                                              Small                                                                              Fine                                                 K   49.sup.7                                                                           Yes  Some  Small to                                                                           Slightly                                                                           1.84 34     .120                                                                             .134                                                                             .140                                                                             .147                                           Medium                                                                             Coarse                                               L   48.sup.7                                                                           No   None  Small                                                                              Fine 1.81 17     .115                                M   53.sup.8                                                                           No   None  Small                                                                              Fine                                                 N   L-5340.sup.9                                                                       No   None  Small                                                                              Fine 1.89 22     .120                                                                             .143                                                                             .153                                                                             .164                       __________________________________________________________________________     .sup.1 From acetic anhydride capping treatment.                               .sup.2 Of example 6.                                                          .sup.3 Of example 11.                                                         .sup.4 Of example 2.                                                          .sup.5 Prepared in the same manner as Surfactant No. 45 of Example 11 but     not capped.                                                                   .sup.6 Prepared in the same manner as Surfactant No. 47 of Example 11 but     not capped.                                                                   .sup.7 Of example 12.                                                         .sup.8 Prepared in the same manner as Surfactant No. 50 of Example 12 but     not capped.                                                                   .sup.9 L5340 = silicone surfactant available from Union Carbide               Corporation.                                                                  .sup.10 Units = Btuin/hr-ft.sup.2°F.                              

EXAMPLE 14

This example illustrates the synthesis of a polyurethane foam utilizingas surfactant a polyol maleate diester surfactant of the presentinvention.

A. Preparation of Ethoxylated Castor Oil-Ditridecyl Maleate Surfactant

To a 500 ml resin kettle equipped with an overhead stirrer andcontaining 200 g of Flo Mo 36 C (ethoxylated castor oil) were added 50 gditridecyl maleate and 6 g 1,1-bis(t-butylperoxy)cyclohexane (availablefrom Witco Chemical Company under the tradename USP-400P). The mixturewas then heated to 110° C. for 4 hours under nitrogen to yield a viscousliquid surfactant of the invention (Surfactant No. 54).

B. Polyurethane Foam Synthesis

In the foam synthesis, the following quantities of the followingingredients were combined as indicated:

    ______________________________________                                                                      Quantity                                        Item    Ingredient            (grams)                                         ______________________________________                                        A       polymethylene polyphenyl isocyanate                                                                 174.8                                           B       urethane polyol       100                                             C       flame retardant       30                                              D       CFCl.sub.3            61.9                                            E       Surfactant No. 54 of Example 14A                                                                    2.0                                             F       amine catalyst        2.0                                             G       tin catalyst          0.14                                            ______________________________________                                    

A large batch of polyol premix was prepared by mixing together items B,C, and D (ca. 1 gal) and cooling the resulting mixture to 15° C. In thefoam synthesis, 191.9 g of the polyol premix at a temperature of 15° C.was poured into a reaction vessel. 2.0 g Item E, 2.0 g Item F and 0.14 gItem G were then added to the vessel, and all ingredients were mixed at1000 rpm for ca. 10 seconds. 174.8 g Item A was then added to the vesseland all ingredients were mixed at 3500 rpm for 10 seconds, andthereafter poured into a box to yield a rigid polyurethane foam.

In the above synthesis, Item A is a polymethylene polyphenyl isocyanatehaving a viscosity of 150-250 centipoises at 25° C. and is availablefrom the Mobay Chemical Company, Pittsburgh, Pa. under the trade nameMONDUR MR.

Item B is that supplied by the Olin Corporation under the trade namePoly G-71-530.

Item C is that supplied by the Olin Corporation under the trade nameRF-230.

Item F is that supplied by Abbott Laboratories under the trade namePolycat 8.

Item G is that supplied by Cincinnati Milacron under the trade name TM181.

The characteristics of the polyurethane foam produced are as follows:

                  TABLE X                                                         ______________________________________                                        Evaluation of Surfactant in Urethane                                                FRI-                                                                    DEN-  ABILITY                                                                 SITY  % wt. loss,                                                                              K-FACTOR* AFTER                                              pcf   10 min.    1 day   7 days                                                                              14 days                                                                             28 days                                                                             56 days                            ______________________________________                                        2.04  13         .122    .133  .139  .142  .149                               ______________________________________                                         *Units = Btuin/hr-ft.sup.2°F.                                     

EXAMPLE 15

This example illustrates the practice of the process of the presentinvention on a commercial scale by reference to FIG. 1 of the drawings.The following quantities of the following ingredients are combined asindicated:

    ______________________________________                                        Item   Ingredient          Parts by Weight                                    ______________________________________                                        A      Polymethylene polyphenyl                                                                          277                                                       isocyanate                                                             B      CFCl.sub.3          49.5                                               C      Diethylene glycol   32                                                 D      Surfactant No. 48 of Example 12                                                                   2.5                                                E      Catalyst mixture of Example 13                                                                    10                                                 ______________________________________                                    

Items A, B, and D are mixed with each other and placed in the tank 11.Item C is placed in the tank 12. Item E is placed in the tank 13. Theapparatus 10 is provided with kraft paper/aluminum foil rolls 30, 31.The oven 35 is heated to a temperature of 150°-200° F. The rolls 38, 39are started, as well as the pumps 17, 18, and 19 to discharge thecontents of the tanks 11, 12, 13 into the respective feed lines whichcarry the ingredients to the mixing head 29. The mixing head 29 depositsthe foam forming mixture onto the lower substrate and both upper andlower substrates and foamable mixture are then conveyed into the oven 35to produce a laminated structural panel 55 of the present invention.

In the above foam synthesis, the polymethylene polyphenyl isocyanate isthat supplied by the Upjohn Company under the trade name Code 047.

Whereas the present invention has been described with respect tospecific embodiment thereof, it should be understood that the inventionis not limited thereto, as many modifications thereof may be made. Itis, therefore, contemplated to cover by the present application any andall such modifications as fall within the true spirit and scope of theappended claims.

I claim:
 1. A foam material comprising the reaction product of:A. polyisocyanurate polymer forming reactants, B. a blowing agent, and C. a surfactant which comprises the reaction product of(a) a polyoxyalkylene adduct having the formula

    H--polyoxyalkylene chain).sub.t R,

wherein R is an organic or inorganic radical and t is the number of polyoxyalkylene chains reacted onto R, and (b) an esterified unsaturated dibasic acid having the formula

    T.sup.1 O.sub.2 C--C.sub.u H.sub.2u-2 --CO.sub.2 T.sup.2

wherein u is 2 or 3 and T¹ and T² are identical or different and represent a straight or branched, saturated or unsaturated hydrocarbon chain, in the presence of an effective amount of a free-radical initiator, and wherein the polyoxyalkylene adduct optionally is capped by treatment either before or after the free-radical initiated reaction with a capping agent capable of reacting with the hydroxyl groups of said adduct, whereby the hydroxyl number of said adduct is reduced to less than
 50. 2. The composition of claim 1 wherein the esterified unsaturated dibasic acid has the formula

    T.sup.1 O.sub.2 C--C.sub.u H.sub.2u-2 --CO.sub.2 T.sup.2

wherein u is 2 or 3 and T¹ and T² are identical and represent a straight or branched, saturated or unsaturated hydrocarbon chain of 4 to 18 carbon atoms.
 3. The composition of claim 2 wherein T¹ and T² represent a straight or branched, saturated or unsaturated hydrocarbon chain of 8 to 18 carbon atoms.
 4. The composition of claim 3 wherein the esterified unsaturated dibasic acid is a member selected from the group consisting of dioctyl maleate, ditridecyl maleate and dioleyl maleate.
 5. The composition of claim 1 wherein t is an integer from 1 to 8 and the molecular weight of the polyoxyalkylene adduct is above about
 1000. 6. The composition of claim 1 wherein the polyoxyalkylene adduct is capped by treatment either before or after the free-radical initiated reaction with a capping agent capable of reacting with the hydroxyl groups of said adduct, whereby the hydroxyl number of said adduct is reduced to less than
 50. 7. The composition of claim 6 wherein the hydroxyl number of said adduct is reduced to less than
 10. 8. The composition of claim 1 wherein an organo transition metal catalyst is additionally present in the free-radical initiated reaction mixture.
 9. The composition of claim 1 wherein the esterified unsaturated dibasic acid comprises about 5 to 40 weight percent of the free-radical initiated reaction mixture, and the initiator comprises from about 2 to 30 weight percent, based on the weight of the esterified unsaturated dibasic acid.
 10. The composition of claim 1 wherein the polyoxyalkylene adduct is a member selected from the group consisting of(a) an alkoxylated amine having the formula: ##STR13## wherein R¹ is independently an alkoxylated chain having the formula: ##STR14## s is an integer from 2 to 10 inclusive and the ratio p:q is from 10:90 to 90:10, the molecular weight of said alkoxylated amine being from about 1500 to 12,000, (b) a linear block copolymer of ethylene oxide and propylene oxide, the molecular weight of said block copolymer being above about 2000 and the ethylene oxide content being from about 30 to 80 weight percent, and (c) an ethoxylated castor oil.
 11. The composition of claim 10 wherein the esterified unsaturated dibasic acid has the formula

    T.sup.1 O.sub.2 C--C.sub.u H.sub.2u-2 --CO.sub.2 T.sup.2

wherein u is 2 or 3 and T¹ and T² are identical and represent a straight or branched, saturated or unsaturated hydrocarbon chain of 8 to 18 carbon atoms.
 12. The composition of claim 11 wherein the polyoxyalkylene adduct is capped by treatment either before or after the free-radical initiated reaction with a capping agent capable of reacting with the hydroxyl groups of said adduct, whereby the hydroxyl number of said adduct is reduced to less than
 10. 13. The composition of claim 12 wherein the capping agent is acetic anhydride.
 14. The composition of claim 13 wherein the esterified unsaturated dibasic acid is a member selected from the group consisting of dioctyl maleate, ditridecyl maleate and dioleyl maleate.
 15. The composition of claim 13 wherein(a) the polyoxyalkylene adduct is ethoxylated castor oil, and (b) the esterified unsaturated dibasic acid is a member selected from the group consisting of dioctyl maleate, ditridecyl maleate and dioleyl maleate.
 16. The composition of claim 15 wherein(a) the ethoxylated castor oil contains from about 25 to 60 moles of ethylene oxide per mole of oil, and (b) the esterified unsaturated dibasic acid is ditridecyl maleate.
 17. The composition of claim 16 wherein the ethoxylated castor oil contains from about 35 to 40 moles of ethylene oxide per mol of oil, the ditridecyl maleate comprises about 5 to 40 weight percent of the free-radical initiated reaction mixture and the initiator comprises from about 2 to 30 weight percent, based on the weight of the ditridecyl maleate. 